Gear housing on propeller assembly for boats



Jan. 9, 1968 K. A. BERGsTl-:DT v 3,362,246

GEAR HOUSING ON PROELLER ASSEMBLY FOR BOATSl Filed July 13, 1965 5 Sheets-Sheet l FIG. 1

s nl M ATTOR NEY ,gunna-...unn-

Jan. 9, 1968 K. A. BIERGsTl-:DT` 3,362,246 GEAR HOUSING ON PROPELLER ASSEMBLY FOR BOATS 5 Sheets-Sheet 2 Filed July l5, 1965 f n l 1 n I J ATTQRNEY Jan- 9, 1958 V K. A. BERGSTEDT 3,362,246

GEAR HOUSING ON PROPELLER ASSEMBLY FOR BOATS Filed July 13, 1965v 5 Sheets-Sheet 3 viv-MLM@ ATTO R NEY United States Patent O 3,362,246 GEAR HGUSING N PROPELLER ASSEMBLY FOR BOATS Karl Abdon Bergstedt, Goteborg, Sweden, assignor to AB Volvo Penta, Goteborg, Sweden Filed July 13, 1965, Ser. No. 471,683 Claims priority, application Sweden, July 14, 1964, 8,595/ 64 9 Claims. (Cl. 74-378) ABSTRACT 0F THE DISCLOSURE A gear housing on the propeller assembly for boats Where t-he engine is located inside the boat and arranged to drive through a gear located in the gear housing and power the propeller through a drive device which extends through the transom of the boat and is connected with a propeller housing which can tilt up and also can turn so as to steer the boat.

The gear housing of this type has earlier been located outside the boat and in cases where the complete propeller housing could be turned and tilted up, the drive must be transmitted through a universal joint which implies certain disadvantages including one whereby the angle of tilt is limited but suggestions have also been made to arrange the gear housing so that it could not be turned around the steering shaft and instead only turn the lower part of the propeller housing for steering purposes, an extra intermediary gear being fitted in order to permit tilting up. In this case gears have been arranged in the gear housing beside each other whereby the result is a disadvantage in that the propeller housing is displaced laterally relative to the engine shaft. However the gear housing in both cases is subjected to the influence of the surrounding water this making inspection and maintenance troublesome.

One model of the invention is described in more detail with reference to the enclosed drawings in which:

FIG. l shows a longitudinal section through a propeller installation,

FIG. 2 shows a section through a gear housing with component parts,

FIG. 3 shows a section through the actual gear housing in FIG. 2 at right angles to this,

FlG. 4 shows a plan of the gear housing in FIG. 3, and

FIG. 5 is fragmentary view corresponding to a portion of FIG. 2 illustrating a modified embodiment of the invention.

Through the invention, which concerns an installation of the last-mentioned type, the above-mentioned disadvantages are eliminated and instead the result is that the gear housing can be located in a protected position in the point of penetration through the transom and the invention is mainly characterized by the fact that an input drive shaft 3 is carried in an outer housing section 21 Which -concentrically encloses an inner housing section 45 in which an output shaft 6 is carried, and also by the fact that this inner housing for the tilting up of the propeller housing 8 can be turned relative to the outer housing section 21 around a connecting shaft 9 at right angles to the input and output shaft, whereby the inner housing 45 is fitted with a radial intermediary partition 55 for the axial location of a gear 39 fitted on the con- 3,362,246 Patented Jan. 9, 1968 necting shaft 9, this gear being in mesh with a further gear 5 on the output shaft 6.

From a suitable engine 19 of the type desired built into the rear of the boat, driving power is taken out through a shaft 3 connected to and forming an extension of engine shaft 19 and journalled in a gear housing 2. The gear housing 2 is supportingly connected to transom 1, and drive shaft 3 terminates in the housing in a bevel gear 4. The 4gear housing has a built-in reduction and reverse gear with the necessary clutch and control devices and from there the driving power is taken over a bevel gear 5 to an intermediary shaft 6 in a propeller housing 7. This propeller housing or outboard leg consists of two parts, of which the upper 8 can be swung upwardly from its downwardly inclined position shown4 to a generally horizontal rearwardly extending position, while the lower part 10 with the propeller 15 is journalled in the part 8 so that it can be turned and swings about the axis of shaft 6 to steer the boat through the links 11, 12 and 13 Ifrom a tiller 14.

Housing section 21 is bolted by bolts such as boit 70 to a supporting shell 71 closing the transom opening 72. Shell 71 is fixed to the transom by suitable means not shown.

FIG. 2 shows the gear housing 2 in more detail. The shaft 3 with the gear 4 is carried in an outer housing section 21, which also contains two intermediate gears 22 and 23 carried in ball bearings on a hollow hub 24 and 25 respectively, these intermediary gears being turned to face each other and being in mesh with gear 4. Through the hub 24, 25 there is a connecting shaft 9 at right angles to shaft 3 which is carried in the hub mentioned by means of plain bearings 73. The hub 24, 25 carries on each outer end an outer cone 26 and 27 respectively for a friction clutch which also includes the inner cones 28 and 29 respectively which are carried on the connecting shaft 9 by means of helically threaded spindles 30 with a steeply inclined pitch. The cones 28 and 29 are internally threaded to screw along their respective spindles 30. A control mechanism for the friction clutches consists of a pivoting arm 31 in the gear housing 2, the arm being fitted with an eccentricaly journalled suitable key-forming pin 32 which engages in a corresponding peripheral slot 33 in the inner cone 28. The inner cones 28, 29 are connected together by means of a bolt 34 through the shaft 9, both ends of the bolt being secured in washers 35, 36 on the ends of the cone. The lock screws 37, 38 which extend through the washers 35, 36 into the cones 28 and 29, prevent the inner cones from turning. When the arm 31 is reset, the key-formed pin 32 swings in directions toward and away from shaft 3 and, in cooperation with the slot 33 in the inner cone 28, displaces the inner cone in one and the other axial direction. Since both the inner cones 28 and 29 are rigidly connected with each other by means of the bolt 34, the washers 35, 36 and the lockscrews 37, 38 both the inner cones are displaced simultaneously in the selected directions. When one of the inner cones 28 or 29 is engaged by friction with the mating outer cone 26 and 27 respectively, it starts rotating and carries with it the connecting shaft 9 through the respective spindle 30, the spindles being integral with shaft 9. At the same time the respective threaded spindle 30 lpresses the inner cone 28 or 29 hard against the respective inner cone 26 or 27 so that a hard friction mesh results.

Through the axial displacement of the inner cones 2S and 29, the connecting shaft 9 can thus be connected as required to the gear input shaft 3, either over the intermediary gear 22 or the intermediary gear 23 so that the connecting shaft 9 can be selected to drive in a forward or reverse direction as selected by arm 31. It will be seen that, as shown in FIG. 3, the pin 32 is centered with neither clutch engaged and, accordingly with the transmission in neutral position.

Between the opposed bevel intermediary gears 22 and 23 there is a further bevel gear 39 which is keyed onto the connecting shaft 9 and this gear is in mesh with the gear on the output shaft `6. The propeller 15 can thus be driven in both directions through the gear in the gear housing 2.

The outer housing section 21 has mainly the form of a circular cylinder and is fitted on the outside with lugs 40 to take bolts such as bolt 70 through which the gear housing 2 is fitted in opening 72 in the transom 1 on the boat. The outer housing section 21 also includes a pair of Icentrally located bearing sleeves 41, 42 for the ball bearings 43, 44 which carry the tubular hub sections 24, 25 of the opposed bevel intermediary gears 22 and 23.

An inner housing section 45 which is similarly mainly in the form of a circular cylinder, has its edges 46, 47 carried round the external surfaces of the bearing sleeves 41 and 42 and the outer surface of the inner housing section 45 is surrounded with a suitable clearance by the outer housing section 21. Since all the component parts in the gear installation associated with shaft 9 and the clutch elements are concentric with both the housing sections 21 and 45, the inner housing section 45 can be turned in a vertical plane with the bearing sleeves 41 and 42 of the outer housing section 21 as a shaft.

The inner housing section 45 has its casing surface fitted with an opening 48 in which the upper part 8 of the propeller housing is attached and the output shaft 6 which is journalled in this unit extends through the opening 48 on the inner housing section 45 to mesh wit-h the bevel gear 39.

Opposite this opening 48 the casing surface of the inner housing 45 has a further opening 49 which is mainly rectangular and extends over a considerable portion of the casing surface, for example half the surface. The function of this opening 49 is to take up the input shaft 3 with such a large clearance in the direction peripherally around the inner housing that the inner housing section 45 can be turned through a sufficiently large angle in the outer housing section 21 to permit the propeller housing to swing up to a sufficient extent.

The surface on the casing of the outer housing section 21 has also a small opening 50 in which the input shaft 3 is journalled and a larger rectangular opening 51 which covers a relatively large part of the casing surface and is intended with a large clearance peripherally around the outer housing to pass the upper section of the propeller housing 8 as the leg tilts. This last-mentioned opening 51 is, however, not located diametricaly opposite the small opening 50 but at such an angle to it that when the upper section of the propeller housing 8 is close to the lower axial edge of the opening, it is in its normal operating position.

Sealing between the outer and inner housing sections must be dependable since the device is to be used in salt water. For this reason the cylindrical surface on the inner housing section 45 which faces outwards has a groove with a mainly-circular cross-section, this groove being designed for an endless sealing cord 52 or rubber or the like. The groove includes two pairs of parallel components, one pair of which runs axially close to the axial edges of the long opening while the two other components extend peripherally along the end edges of the casing surface in such a way that the small opening 48 for the output shaft 6 is surrounded by the sealing cord. The separate parts of the groove have a smooth transition into each other.

The outer housing section 21 is fitted with a similar groove for an endless sealing cord 53. This groove runs close to the edges on the long opening 51 in the outer housing section 21 and is located completely outside the groove on the inner housing section 45. This means that it is possible to turn the inner housing section 45 in relation to the outer housing section 21 and thereby swing the propeller housing vertically without the two endless sealing cords 52 and 53 forming any obstacle for each other.

The axial end edges of the long opening 51 in the outer housing section 21 are fitted with scraper knives 54 the edges of which are in contact with the casing surface of the inner housing section 45 and keep this free from seaweed, seashells, and similar foreign matter.

The inner housing section 45 is finally also fitted with a central intermediate partition 55 which is drilled centrally, the connecting shaft 9 extending through this hole. This intermediate partition functions as a support for the axial ball bearings 56, 57, the function of these being to retain the connecting shaft 9 in a firm axial position so that the mesh between the gears 39 and 5 is always maintained constant.

The design described above makes possible both steering of the boat and tilting up of the propeller housing without it being necessary to use any extra universal joints or gear installations and so that the input drive shaft and the output shaft are in the same plane, whereby detrimental torque loading is avoided.

An alternative seal beween inner housing member 45 and the outer housing 21 is illustrated in FIG. 5. In this modification sealing cords 52 and 53 and the grooves for receiving the cords are omitted, together with scraper 54, and a loose continuous open ended bellows 75 is substituted. The skirt or edge 76 of the bellows is sealed against housing 21 completely around opening 51 thereof by means of a retainer 77 bolted by bolts 78 to the housing and holding the skirt against the housing. The opposite edge or skirt 79 is sealed around the propeller shaft housing 8 by a retainer or clamp 80 in the manner of a hose clamp, the clamp being held in place to the housing by one or more bolts 81. The bellows may be of rubber or other suitable flexible waterproof sheet material and, being sealed at one open end around opening 51 and at the other open end around the propeller shaft housing, prevents water from entering opening 51 while permitting the housing 8 to tilt freely. Except as indicated, it will be understood that the construction of FIG. 5 is in accord with the foregoing description of FIGS. l-4 and that the specific view corresponds to the lower portion of FIG. 2.

Further details of the device herein disclosed are described in my copending U.S. application Ser. No. 431,332, filed Feb. 9, 1965, now abandoned, and in my copending U.S. application Ser. No. 609,991, filed on Ian. l0, 1967, as a continuation thereof.

While only certain preferred embodiments of this invention have been shown and described by way of illustration, many modifications will occur to those skilled in the art and it is, therefore, desired that it be understood that it is intended in the appended claims to cover all such modifications as fall within the true spirit and scope of this invention.

What is claimed as new and what it is desired to secure by Letters Patent of the United States is:

1. In an inboard-outboard boat drive comprising an outboard leg including an upper and a lower portion, an output shaft in said leg, a propeller mounted on said lower portion drivingly connected to said shaft, the lower portion being rotatably connected to the upper portion for rotation about the axis of said shaft for steering, an inboard engine having a rearwardly extending drive shaft terminating in first drive gear, said shafts having axes lying in the same vertical plane, a connecting shaft extending transversely of said plane, spaced apart reverse and forward drive gears rotatably entrained on said connecting shaft and disposed in opposed relationship with respect to and in mesh with said first drive gear and driven thereby in respectively opposite directions, clutch means for selectively clutching said forward and said reverse drive gears to said shaft, said output shaft having an upper end, and a driven gear fixed on said upper end, a driving gear disposed between said forward and reverse gears keyed to said Iconnecting shaft and in mesh with said driven gear, a hollow inner gear housing having a cylindrical outer surface and a hollow outer gear housing having a cylindrical inner surface, said inner housing being fitted within said outer housing and being rotatable with respect thereto, said gear housings being disposed with their cylindrical axes coincident with the axis of said connecting shaft, said driven gear, driving gear, first drive gear, and said forward and reverse drive gears Iand said connecting shaft being disposed within said inner gear housing, one of said gear housings being rigidly connected to said upper leg portion and the other of said gear housings being rigidly connected to the boat, said one gear housing having an opening through which said engine drive shaft extends, said other gear housing having an opening through which said output shaft extends, said openings being enlarged peripherally around said housings to provide celarance for the respective shafts therethrough whereby said leg is free to tilt up about said laxis of said connecting shaft, and positioning means for retaining said driving gear in meshed position with respect to said driven gear comprising an inwardly extending partition on said one gear housing disposed beween said forward and reverse gears and a bearing engaged between said partition and said driving gear locating said driven gear with respect to said partition.

2. The combination according to claim 1 wherein said outer gear housing is rigidly connected to the boat and said inner gear housing is rigidly connected to said upper leg portion.

3. The combination according to claim 2 further comprising a flexible liquid-tight bellows having opposite open ends, means sealing one of said ends to said outer gear housing completely around said enlarged opening thereof, and means sealing the other end of said -bellows completely around said upper leg portion.

4. The combination according to claim 1 wherein said forward and reverse gears are mounted for rotation in bearings carried by said other gear housing and maintaining said forward and reverse gears in predetermined rotative positions therein.

5. The combination according to claim 1 wherein said bearing connects said connecting shaft to said partition and fixes said connecting shaft against axial displacement with respect to said partition, and wherein said driven gear is fixed on said shaft.

6. The combination according to claim 1 where a respective bearing is provided in said other housing journalling said forward and said reverse gears in fixed rotative positions in said other housing, a respective sleeve bearing is provided in said forward gear and in said reverse gear, and said connecting shaft is journalled in said sleeve bearings.

7. The combination according to claim 1 wherein one of said housing surfaces has a continuous groove therein extending completely around the enlarged opening of the respective housing and a continuous sealing cord is disposed in said groove slideably and sealingly engaging the other of said housing surfaces.

S. In an inboard-outboard boat drive comprising an outboard leg including an upper and a lower portion, an output shaft in said leg, a propeller mounted on said lower portion drivingly connected to said shaft, the lower portion being rotatably connected to the upper portion for rotation about the axis of said shaft for steering, an inboard engine having a rearwardly extending drive shaft terminating in a first drive gear, said shafts having axes living in the same vertical plane, a connecting shaft extending transversely of said plane, spaced apart reverse and forward drive gears rotatably entrained on said connecting shaft and disposed in opposed relationship with respect to and in mesh with said first drive gear and driven thereby in respectively opposite directions, clutch means for selectively clutching said forward and said reverse drive gears to said shaft, said output shaft having an upper end, and a driven gear fixed on said upper end, a driving gear disposed between said forward and reverse gears keyed to said connecting shaft and in mesh with said driven gear, a hollow inner housing having a cylindrical outer surface and a hollow outer gear housing having a cylindrical inner surface, said inner housing being fitted within said outer housing and being rotatable with respect thereto, said gear housings being disposed with their cylindrical axes coincident with the axis of said connecting shaft, said driven gear, driving gear, first drive gear, and said forward and reverse drive gears and said connecting shaft being disposed within said inner gear housing, one of said gear housings being rigidly connected to said upper leg portion and the other of said gear housings being rigidly connected to the boat, said one gear housing having an opening through which said engine drive shaft extends, said other gear housing having an opening through which said output shaft extends, said openings being enlarged peripherally around said housings to provide clearance for the respective shafts therethrough whereby said leg is free to tilt up about said axis of said connecting shaft, positioning means for retaining said driving gear in meshed position with respect to said driven gear, said outer surface of said inner gear housing having a continuous groove therein, said inner surface of said outer housing having a continuous groove therein, said grooves extending completely around the enlarged opening of the respective housing, and a respective continuous sealing cord in each said groove, the cord in the groove of the inner housing slideably and sealingly engaging the inner sur-face of the outer housing and the cord in the groove of the outer housing slidably and sealingly engaging the outer surface of the inner housing.

9. In an inboard-outboard boat drive comprising an outboard leg including an upper and a lower portion, an output shaft in said leg, a propeller mounted on said lower portion drivingly connected to said shaft, the lower portion being rotatably connected to the upper portion for rotation about the axis of said shaft for steering, an inboard engine having a rearwardly extending drive shaft terminating in a first drive gear, said shafts having axes lying in the same vertical plane, a connecting shaft extending transversely of said plane, a forward drive gear rotatably entrained on said connecting shaft and in mesh with said first drive gear and driven thereby, clutch means for selectively clutching said forward drive gear to said shaft, said output shaft having an upper end, and a driven gear fixed on said upper end, a driving gear keyed to said connecting shaft and in mesh with said driven gear, a hollow inner gear housing having a cylindrical outer surface and a hollow outer gear housing having a cylindrical inner surface, said inner housing being fitted within said outer housing and being rotatable with respect thereto, said gear housings being with their cylindrical axes coincident with the axis of said connecting shaft, said driven gear, driving gear, first drive gear, and said forward drive gear and said connecting shaft being disposed within said inner gear housing, said inner gear housing being rigidly connected to said upper leg portion and said outer gear housing being rigidly connected to the boat, said inner gear housing having an opening through which said engine drive shaft extends, said outer gear housing having an opening through which said output shaft extends, sad openings being enlarged peripherally around said housings to provide clearance for the respective shafts therethrough whereby said leg is free to tilt up about said axis of said connecting shaft, a flexible liquid-tight bellows having two opposite open ends, means sealing one said References Cited UNITED STATES PATENTS 1,184,944 5/ 1916 Gettelman. 2,708,416 5/1955 Schmitter 74-379 X 2,737,920 3/1956 Heath 74-385 X 8 8/1960` Cattaneo et al 74-385 10/1965 Bergstedt 74-378 11/ 1965 Shimanckas.

8/ 1966 Bergstedt 74-378 X FOREIGN PATENTS 2/1963 France.

DONLEY J. STOCKING, Primary Examiner.

L. H. GERIN, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,362,246 January 9, 1968 Karl Abdon Bergstedt It s hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 5, line 25, for "celarance" read clearance llne '75, for "living" read lying column 6, line ll, after "inner" insert j gear Signed and sealed this 11th day of February 1969.

(SEAL) Attest:

Edward M. Fletcher, Jr. EDWARD J. BRENNER Attesting Officer Commissioner of Patents 

